Читать книгу Cucurbits - James R. Myers - Страница 11

Most cucurbit seedlings are epigean, germinating with the tips of the cotyledons initially inverted but later erect. As it emerges, the hypocotyl straightens and the cotyledons ascend as the seed coat is dislodged by the peg, an outgrowth on one side of the hypocotyl. The function of the peg is to open the seed coat and permit the cotyledons to emerge. The photosynthetic cotyledons of most cucurbit seedlings are more or less oblong in shape. Between them lies the inconspicuous developing epicotyl.